Adjustable Second Stage??? Good idea???

[cougar]

I liked the gear I had....but since it all got kidnapped from B&B Caribo in Cozumel...I have to go shopping again.

I often wished I had a cool adjustment on my second stage. It would be nice to be able to choose how hard I want it to breath. What regulators have this feature and do you think it's a good idea? The only adjustment on my former reg would have consisted of opening things up and using tools.

This will be usually warm water diving...both nitrox and air...what is your opinion?

 

[redacted]

cougar once bubbled...

I often wished I had a cool adjustment on my second stage. It would be nice to be able to choose how hard I want it to breath.

Save your money if that is what you want. With the exception of surf or strong current, there is no reason to have your reg breath any worse than its easiest setting.

But the balanced adjustable second design (attached to a high performance balanced 1st) seems to be the standard for ease of breathing and volume of gas delivered. They are more complex than the much cheaper classic downstream valve design, and for simple recreational diving it may be hard to tell the difference. But when challenged by more severe conditions, like swimming into current or helping a buddy, the difference in performance is readily apparent. The balanced poppet second can be had from a number of mfgrs with or without the adjuster. If you don't dive surf or current, the adjuster may not be worth the extra $50.00 or so. Although the adjuster is also useful if you are soaking a balance poppet 2nd without it being pressurized to push the seat againt the orifice to keep water out of the system.

At least one mfgr has an adjuster on a classic downstream design. Overall performance is below a balanced poppet design but it will have the same effect in current & surf.

Decision should be do you need a high performance reg? That adds hundreds to the cost. Then decide if the adjuster is worth the extra fifty.

 

[rmediver2002]

Most are not really adjustable in the technical sense, they modify the air route through the second stage causing a venturi effect.

These regulators are set at such a low negative pressure requirement they will give the illusion of becoming easier to breathe or even begin to free flow when adjusted to more air if they are purged.

If you are really interested in an adjustable regulator try checking into the Kirby Morgan line. http://www.kmdsi.com/scuba.html

Check this link out, these regulators actually adjust the spring tension on the seat allowing a adjustment from high resistance to free flow and anything in between.

I do not know of any other manufacturer offering anything comparable as far as adjustment.

Hope this helps, I am sorry to hear your equiment was stolen...

Jeff Lane

 

[rmediver2002]

I would agree with AWAP to save your money on this one...

 

[mddolson]

The only time I can honestly say I needed adjustable 2nd stages, is on my 2 Buddy phones.
I have the half mask version, that has a chin or mouth mask.
The added water colume created by extending the distance from my mouth to regulator causes them to free flow readily, at the normal setting. The adjustment knob allows the user to de-tune the regulator, to adjust for the added water column in the mouth-mask.

Otherwsie I have consider adjustable (scubapro R190) second stages to be a toy you fiddled with from time to time.

Mike D

:blfish:

 

[Norm]

You are correct, they do look cool. In actuality, they are seldom used. Some uses: 1.To detune a reg in need of adjustment, (has experienced some wear but nothing requiring a rebuild yet).
2.To detune a reg that is freeflowing because you are riding a scooter and going head-first into a blowing cave or extremely strong ocean or river current. 3.To make a reg slightly easier to breath off of, (because it needs a slight adjustment). 4.To shut off a second stage that has frozen open, (and if this is the case - it doesn't always shut it off!).

There are several companies offering adjustment knobs on their second stages.
Some have a knob which only contols senstivity to freeflow. In reality, these are used constructively more than the fancy knobs to control flow. (They're great!) They are used to control an octopus and keep it from freeflowing during entries or non-use during a dive. All I have seen do this quite nicely.
Some have a knob which contols breathing effort and/or flow. There some which actually do adjust the breathing effort. (The ones I know of are all on balanced second stages) They work great! There are some knobs which do nothing more than adjust the second stage seat or orifice. This is nothing different than what your LDS tech does when he makes an adjustment for you. (Some can actually damage your poppet seat if you are not: 1.Pressing the purge button when you turn them or 2.Inhaling while you are turning them!
One advantage to either of these flow-adjustment knobs: They can be backed off, all the way during storage, to help extend seat life and adjustment! (One brand I know of supposedly does this automatically when depressurized)

I guess I am saying that the knobs can be superb or they can not only be useless - they can actually hurt your reg's performance! Alot of it comes from knowing about your particular brand and model before you buy. I've seen, (and even owned), regs that went for years without any service or adjustments....or knobs!

Norm

 

[dgangi]

Correct me if I am wrong, but what mid- to high-end regulators DON'T come with an adjustible second stage? My Oceanic Delta 3 has it, my friend's Atomic Z1 and T1 both have it...

...and when I was shopping regulators, almost every model from Scubapro, Apeks, Atomic, Oceanic, Aqualung, and Zeagle had this second stage adjustment knob.

The *only* regs that don't have these are the cheaper models. The Oceanic Gamma 2 that my wife has does NOT have this adjustment knob. Nor do some of the cheaper models from other manufacturers.

So the bottom line is this -- if you are in the market for a mid- or high-end regulator (something that costs >$300), then you're going to get one with an adjustment on the second stage. There isn't really an option...unless you buy a lower end regulator.

(FYI -- in my opinion, the Oceanic Gamma 2 is a fantastic regulator, so if you don't want that knob, then look at that model)

Maybe it's marketing research that is forcing all manufacturers to add these knobs. Maybe it's fashionable. Or maybe it's just that all manufacturers have to be like everybody else. Who knows. But they're here for the time being.

Thx...Doug

 

[cybordolphin]

Get one that has the adjustment knob if that is what you want.
There is no reason not to.

You can find a reg with the adjustment you want .... in just about any price range. I take it you are not really looking to just spend a hundred bucks, and so.... I think you can easily find what you want. I paid only $320.00 for my Apeks ATX200, and they can be had for $375.00 all day long. You might also check out the Scubapro S600, as they received a pretty good write up on Rodales recently. These can be had for about the same price, coupled with the MK25 or MK18UL.... looks to be an outstanding performer.